Canon 8468B023 Manual page 30

When loading envelopes or preprinted paper, see
4
Align the paper guides against the edges of the paper.
Align the paper guides securely against the edges of the paper.
Align the paper guides securely against the paper
Paper guides that are too loose or too tight can cause misfeeds or paper jams.
After reloading paper that has run out during printing, or resetting the paper after a paper error notification, press the
key to restart printing.
Printing on the Back Side of Printed Paper (Manual 2-Sided Printing)
You can print on the back side of printed paper. Flatten any curls on the printed paper and insert it into the multi-purpose tray
with the side to print face up (previously printed side face down).
Load only one sheet of paper each time you print.
You can use only paper printed with this machine.
You cannot print on the side that has been previously printed.
LINKS
Paper
Loading Envelopes or Loading Preprinted Paper.
(Paper)